The MASCOT rover that hopped onto an asteroid after being dropped by a Japanese spacecraft has died, a day after it arrived. The little robot hopped onto the rock known as Ryugu and explored around by hopping across its surface. But it could only do so using its built-in battery, which had less than a full day of charge. In the end, MASCOT lasted more than 17 hours, despite having only 16 hours of forecast time. And it before it shut down it sent back all of its findings to Hayabusa-2, the Japanese spacecraft who carried it the 180 million miles away from Earth and then dropped it onto the asteroid.